[Correlation of hereditary and environmental effects on external respiratory function and its changes during aging in...

The genetic-statistical analysis of 11 variables of the external respiration has been made in 90 twin pairs of the same sex divided into two age groups: 20-44 and 45-80 years. The following classification of indices of the lung ventilation function can be suggested: with high hereditary coefficients that remain unchanged with age, with low coefficients gamma 2 that are the same in both age groups, with increasing hereditary coefficients in aging, and with the high Ignatiev-Jensen criteria in the group of people aged 20-44 and declining ones in the group aged 45-80. The last group of ventilation variables is the largest. In the group aged 20-44 a test with oxygen inhalation increases the effect of environmental factors whereas in the group aged 45-80 it decreases this effect on the indices of the lung ventilation.